Fluid recoil brake for guns



E. c. MORlARTY FLUID RECOIL BRAKE FOR GUNS Filed April 16', 1919.

QN w

Patented Dec. 16, 1924.

ERNEST C. MORIARTY, OF THE UNITED STATES ARMY.

FLUID BECOIL BRAKE FOR GUNS.

Application filed April 16, 1919.

Serial No. 290,596.

(FILED UNDER THE ACT OF MARCH 3, 1883, 22 STAT. L., 625.)

To aZZ whom it may concern:

Be it known that I, ERNEST C. Monnm'rx, Lieut, Ordnance Department, United States Army, a citizen of the United States, stationed at ivashington, District of Columbia, have invented an Improvement in Fluid Recoil Brakes for Guns, of which the following is a specification.

The invention described herein may be used by the Government, or any 'of its oiiicers or employees in prosecution of Work for the Government, or by any other person in the United States, without payment of any royalty thereon.

Nearly all modern heavy ordnance guns, such as cannon and field guns, are equipped with recoil checking mechanism, such as a hydraulic or like liquid brake interposed between the gun and its carriage, in order to absorb the great-er part of the energy of recoil, and also with counter recoil checking mechanism, such a spring or compressed air recuperator, dependent on or independcut of the brake, which stores up the rest of the energy and uses it to return the gun to firing or normal in battery position. The brake is connected, on the one hand, with the gun, either by its piston rod or by its cylinder, and, on the other hand, with the cradle carried by the gun carriage.

My invention relates to this type of recoil guns provided with a recoil brake and with a pneumatic recuperator, the latter comprising a displacer and a compressed air receptacle. In such pneumatic recuperators, the brake-piston working in the brake cylinder forces the liquid from the latter into a dis placer-cylinder containing a free or floating piston, which latter is thereby caused to move to compress the air in a compressed air chamber.

In such fluid recoil checks or brakes and recuperators, itis customary to polish the bores of the brake cylinder and the displacer-cylinder in which the pistons move, so that the bores may be perfectly true and have highly glazed or polished surfaces so that the piston, the packing of which is under exceedingly heavy tension, may reciprocate therein with comparative ease and with a minimum of wear. This polishing of the surface interior of the cylinders is a laborious and troublesome and costly opera tion; and it is the object, therefore, of my invention to devise a construction of fluid recoil check or brake wherein polishing of the brake and displacer cylinders may be dispensed with.

To this end, the invention resides, comprehensively stated, in a brake cylinder and a displacer cylinder, in which move respec tively, a brake piston and a free piston characterized by the fact that they are out of contact with the cylinders or have a loose fit therewith.

More specifically considered, the invention resides in a fluid recoil check or brake comprising a brake cylinder with a piston working therein and sliding in a fixed bushin or stuffing-box seated interiorly of said cylinder, and in which one end of the piston normally rests, the piston being an elongated member, which projects through said stufiing box and beyond the corresponding end of the brake cylinder; and a displacer-cylin'der having a free piston working therein and likewise sliding in a fixed bushing.

The invention also resides in the provision of a tubular guide and guard normally enclosing the major portion of the piston.

The invention is exemplified in the accompanying drawings, which disclose one concrete embodiment of the underlying principles thereof. Like reference characters desgnate corresponding parts throughout the several views. The several views shown in the drawing may be briefly described as follows:

Referring, now, in detail, to the drawings:

Figure l is a horizontal sectional view, .on the line l-1, Figure 2 of my fluid recoil brake;

Figure 2 is a View, in end elevation, thereof.

1 designates the brake cylinder, or hermetic. envelope, containing a suitable liquid,

such as glycerine or oil. and provided, at.

one end, with a fixed stufling box 2 through which slides the: piston rod 4, suitably connected to the gun, as in the usual manner, so as to move therewith during recoil and return. Another fixed packing or stuffingbox 3 is disposed in said brake-cylinder. preferably somewhat removed from the other end thereof. Said stuffing-box may be held against longitudinal movement in one direction by abutting an annular shoulder 3 in the bore of the brake cylinder; and may be held against like movement in the other direction by a tubular guide and guard which abuts, toward its inner end, against the outer end of said stufiing box 3, as shown at 8 The guide 7 has a threaded portion 7, which is screwed into a similarly threaded portion at the end of the brake cylinder. Said piston is an elongated body, as shown, appropriately of lesser diameter than the bore of the brake-cylinder, or of such a diameter to make a. loose fit therewitln F or the sake of lightness, the piston hollowed out, as shownat 6, said recessed portion extendingtrom the outer end thereof to a point near the point of connection with the piston rod l. V

The guide 7 which may be closed, at its outer end, by a screw-cap 8,, normally encloses the major portion of the piston 5, as shown. The piston 5 may be 'arovided, at its outer end, with a collar 5 loosely fitting the tubular guide 7. The guide '7 also acts as a guard to prevent injury of the piston, or deposit thereon of dirt.

By the construction describes, it will be noted that there is no necessity of polishing thebore of the brake cylinder 1, since the piston 5 is out of contact therewith, or has a loose fit therein, in contra-distinction to the ordinary construction, wherein the pistoncontact's and has a tight lit with the wall of the brake cylinder. H

The brake cylinder communicates, at one end thereof, by a port 9, with a displacercylinder 10. The displacer cylinder contains, as usual, the tree or floating piston, not shown, which works through a packing or stalling box, not shown, which stufling box is preferably confined between the interior cylinders 12 and 12 which are forced by suitable means against the stutlinp box,

Because of the provision of the fixed stutling box, the displacer piston may also have a loose fit, or be out of contact, with the wall of the displacer cylinder, as shown, thus :xvoiding the necessity of polishing such cylinder. 7 p

The end of the displacer cylinder 10 opposite'the port 9, communicates, as usual, through a port 11 with the compressed air receptacle 16, preferably in the form or a cylinder. I

The brake-cylinder 1, may be of the special construction herein described and the dis-placer cylinder 10, of ordinary construction, or vice versa; or both oft said cylinders may be of the special construction described.

The operation of this type of fluid recoil brake and recuperator is well known, and my fluid recoil brake and recuperator difters, in operation, in no wise from the well known construction. It is understood. that the fluid recoil brake and recuperator shown in the drawing may, as usual, be disposed inside the customary cradle, carried by the gun carriage, on which the gun slides. The drawing (Fig. 1) illustrates the in battery position at the parts. Upon firing the gun, the ,recoi thereof pulls the piston rod at'toward the right in Fig. 1, thus drawing the piston 5 into the brake cylinder 1 and displacing a volume of the fluid therein, such as oil or glycerine, through the port 9, and forcing the oil in the displacer cylinder 10 to drive the floating displacer piston torwardly, thus further compressing the air in the compressed-air cylinder 16.

Bitter complete recoil, the compressed air forces the floating or tree piston back, thereby returning the displaced oil and driving the piston in the reverse direction and re turning the gun to its normal in battery position.

Having thus tully described my invention. what I claim as new and desire to obtain by Letters Patent is 1. In a gun, recoil brake mechanism therefor, including a brake cylinder, tubular guide mounted in the. brake cylinder and eX- tending forwardly thereof, astuffing box carried by the tubular guide and an elongated piston mounted in the tubular guide for reciprocation through said stalling box.

2. In a gun, recoil brake mechanism therefor, including a brake cylinder, a stutling boxmounted at the rear end oil? the brake cylinder, a tubular guide mounted in the brake cylinder and extending forwardly thereof, a stuffing box mounted in the tubular guide, an elongated piston in the tubular guide and reciprocable through the last mentioned stutlingbox and a piston rod connected to the piston and passing through the first mentioned stuifing box.

ERNEST C. MORIARTY. 

